共焦腔增强的空气拉曼散射

发布时间：2018-04-28 08:35

本文选题：共振共焦腔 + 拉曼散射　；参考：《物理学报》2017年19期

【摘要】：拉曼光谱是一种无损、快速的物质成分分析和检测方法.由于拉曼信号强度微弱,使得拉曼光谱的检测应用受到极大的限制.针对增强拉曼散射信号强度、提高检测灵敏度这一问题,设计了一种用于自发拉曼散射信号增强的共焦腔样品池,开展了基于该共焦腔的空气拉曼散射信号增强研究.共焦腔的腔镜反射率为92%,这一设计在保证共焦腔通带宽度与激光器线宽匹配的同时能有效地降低共振调节难度.实验中采用0°探测构型收集拉曼信号,并由成像式拉曼光谱仪获取光谱信号.实验发现,在共振状态下,共焦腔的耦合效率达到87.5%,单向激光功率实现约11倍放大;与无共振腔相比,共焦腔对拉曼信号实现17倍放大,信噪比提高2倍.此外,空气中CO_2的3σ检测限达到200 ppm量级.结果表明,该系统对自发拉曼散射信号增强效果显著,并且有较高的检测灵敏度.
[Abstract]:Raman spectroscopy is a nondestructive and rapid method for material composition analysis and detection. Because of the weak intensity of Raman signal, the application of Raman spectrum is greatly limited. Aiming at the problem of enhancing the intensity of Raman scattering signal and improving the detection sensitivity, a confocal cavity sample cell for enhancing the spontaneous Raman scattering signal is designed, and the enhancement research of air Raman scattering signal based on the confocal cavity is carried out. The mirror reflectivity of the confocal cavity is 92. This design can effectively reduce the difficulty of resonance regulation while ensuring the matching of the passband width of the confocal resonator with the linewidth of the laser. In the experiment, 0 掳probe configuration is used to collect the Raman signal, and the imaging Raman spectrometer is used to obtain the spectral signal. The experimental results show that the coupling efficiency of the confocal cavity is 87.5 and the unidirectional laser power is about 11 times larger than that of the non-resonant cavity, and the Raman signal is amplified 17 times and the signal-to-noise ratio is 2 times higher in the confocal cavity than in the non-resonant cavity. In addition, the 3 蟽 detection limit of CO_2 in air reaches the order of 200 ppm. The results show that the system has remarkable enhancement effect on spontaneous Raman scattering signal and has high detection sensitivity.
【作者单位】：华中科技大学武汉光电国家实验室;华中科技大学光学与电子信息学院;
【基金】：国家自然科学基金(批准号:61675082)资助的课题~~
【分类号】：O657.37

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